/Engine/Plugins/Online/OnlineSubsystemSteam/Source/Public/OnlineEncryptedAppTicketInterfaceSteam.h
Do note that Steam limits the encrypted application ticket frequency to one per 60 seconds. Trying to encrypt data more often will result in an k_EResultLimitExceeded error. This delegate dictates the success or failure of data encrypting result. On success, this means that the encrypted data is now available and can be retrieved via call to GetEncryptedAppTicket.
typedef TMulticastDelegate_TwoParams< void, bool, int32 > FOnEncryptedAppTicketResponse